In other news: f you look solely at the U.S.'s long record of taking in refugees from countries torn apart by war, it's hard to argue that national security should be a top concern in the debate over Syrian migrants.

In the 14 years since September 11, 2001, the United States has resettled 784,000 refugees from around the world, according to data from the Center for Migration Studies, a D.C. think tank. And within that population, three people have been arrested for activities related to terrorism. None of them were close to executing an attack inside the U.S., and two of the men were caught trying to leave the country to join terrorist groups overseas.

"I think I can count on one hand the number of crimes of any significance that I've heard have been committed by refugees," said Lavinia Lim�n, a veteran of refugee work since 1975 and the president of the U.S. Committee for Refugees and Immigrants. "It just hasn't been an issue."

Yet it is the issue now, as the Obama administration tries to fend off a revolt by Republican governors over its plans to resettle more than 10,000 Syrian refugees escaping the brutality of both the Islamic State and the Assad government. The coordinated attacks in Paris have fanned fears that terrorists could infiltrate the U.S. by slipping in among the refugees-as might have occurred in the case of one of the Paris attackers.

As U.S. officials and refugee advocates point out, that has never happened in modern history. Not when the U.S. took in tens of thousands of Vietnamese refugees in the 1970s. Not when 125,000 Cuban "Marielitos" arrived by boat in 1980. And not in the desperate aftermath of more recent wars in Bosnia, Somalia, or Rwanda. "Those fears have proven unfounded," said John Sandweg, a former acting director of ICE who previously served as a top lawyer at the Department of Homeland Security.

Is there any reason why Syria should be different?

"I think I can count on one hand the number of crimes of any significance that I've heard have been committed by refugees. It just hasn't been an issue." "